<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <script src="jquery-3.1.0.min.js"></script>

</head>
<body>
    <button id="btn1">按钮</button>
   <p>hello world </p>
    <script>
    $(document).ready(function(){
        $("#btn1").click(function(){
            $("p").hide(1000,function(){
                alert("动画结束，这个方法被称为回调");
            });
        });

    });
    </script>
</body>
</html>